package com.gupaoedu.vip.proxy.jdkproxy;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;

/**
 * @Auther: tcm
 * @Date: 2020/1/25 19:43
 * @Description:
 */
public class GPClassLoader extends ClassLoader {

    private File classPathFile;

    public GPClassLoader(){
        String classPath = GPClassLoader.class.getResource("").getPath();
        this.classPathFile = new File(classPath);
    }

    @Override
    protected Class<?> findClass(String name) throws ClassNotFoundException {

        String className = GPClassLoader.class.getPackage().getName() + "." + name;
        if(classPathFile != null){
            File classFile = new File(classPathFile, name.replaceAll("\\.","/"));
            if(classFile.exists()){
                FileInputStream in = null;
                ByteArrayOutputStream out = null;
                try{
                    in = new FileInputStream(classFile);
                    out = new ByteArrayOutputStream();
                    byte[] buff = new byte[1024];
                    int len;
                    while((len = in.read(buff)) != -1){
                        out.write(buff,0,len);
                    }
                    return defineClass(className, out.toByteArray(), 0, out.size());
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        }
        return null;
    }
}
